TM 5-4520-241-14
SECTION IX. MAINTENANCE OF FUEL SYSTEM
4-29.
DESCRIPTION.
a. Fuel Lines and Fittings. There are two nylon fuel lines. One connects the fuel filter to the carburetor inlet port.
The other runs from the top of the carburetor float bowl to the overflow receptacle on the front of the heater. Fittings are
standard brass male, elbow, nipples, and connectors. The heater is designed for use with an external fuel pump, and a
power supply for a fuel pump is provided.
b. Fuel Filter. A bowl-type fuel filter with a replaceable element strains the fuel before it reaches the carburetor.
c. Carburetor. The carburetor controls the fuel flow to the burner. A solenoid valve permits or restricts fuel flow,
while the fuel needle's position in the fuel jet determines the rate of flow. A cartridge-type heater is built into the
carburetor body to preheat fuel when necessary. The float bowl assembly assures a steady supply of fuel to the burner
as well as an overflow relief if the burner cannot accept the fuel. A manual choke is provided for cold weather starting.
d. Solenoid Valve. The solenoid valve is energized to permit fuel flow through the carburetor only when conditions
are correct for combustion.
4-30.
FUEL LINES AND FITTINGS.
WARNING
This space heater contains dangerous voltages which can cause severe electrical
shock. Be sure to disconnect the power plug before repairing the heater.
a. Disassembly.
(1) Disconnect the power plug, and shut off the fuel supply.
(2) Using a wrench, remove the nylon tubing (1, fig. 4-21) from the male elbows (2) by backing off the nuts.
(3) Unthread the three male elbows, two from the carburetor (3) and one from the fuel filter (4).
(4) Remove screws (5), seal caps (6), lock washers (7), and receptacle plates (8). This permits removal of the
two bulkhead fittings (9) from the front of the heater.
(5) Unscrew one bulkhead fitting (9) from hex nipple (10), and then unscrew the nipple from the fuel filter.
4-56
